Heidelberg Materials supplied slag cement for the Fern Hollow Bridge replacement in Pittsburgh, Pennsylvania, supporting the fast, safe replacement of a structure that collapsed in January 2022. The project received a 2024 PCI Design Award in the category “Bridge with a Main Span from 76-200 Feet Honorable Mention.”
After the collapse of the original bridge, state officials approved an emergency proclamation that allowed PennDOT and the City of Pittsburgh to access resources allowing accelerated bridge replacement while ensuring a safe, durable end product. Precast concrete was part of the solution. The design-build project constructed a three-span structure using 21 prestressed concrete 33/95.5 PA bulb-tee beams, each weighing more than 100 tons and measuring roughly 152 ft in length.
As a result, the original project schedule of four-to-five years was dramatically accelerated, and the bridge was completed in less than one year. Prestressed beams, fabricated off site in a controlled environment, are expected to have a service life of more than 100 years, exceeding the American Association of State Highway and Transportation Officials’ minimum 75-year bridge design life.
Precast concrete erection was completed on August 16, 2022.
“Slag cement is an excellent solution for all types of concrete. In the case of the Fern Hollow Bridge Replacement project, it was effectively used to produce precast concrete, which allowed accelerated construction. This high strength concrete provided for rapid bridge replacement and ensured a safe, durable transportation solution,” said Larry Rowland, Sustainability Market Manager, Heidelberg Materials.
Project Team:
- Owner: Pennsylvania Department of Transportation, City of Pittsburgh, Bridgeville & Pittsburgh, Pennsylvania
- Engineer: HDR
- General Contractor: Swank Construction Company
- Precast Concrete Producer: PennStress
- Slag cement supplier: Heidelberg Materials